U-43, 120; A NEW ANTITUMOR ANTIBIOTIC

I. PRODUCTION, BIOLOGICAL ACTIVITY, MICROBIOLOGICAL ASSAY AND TAXONOMY OF THE PRODUCING MICROORGANISM

Abstract

A new antitumor antibiotic, U-43, 120 was discovered. It is produced by fermentation of a new species of Streptomyces, designated Streptomyces paulus DIETZ sp. n. Its antimicrobial activity is limited to bacteria. A microbiological assay with Bacillus subtilis was developed that can detect concentrations of 1-2 μg/ml of the drug in fermentation liquors. U-43, 120 was active in vivo against P-388 leukemia in mice.